I have wireless internet. Can I see if anyone else is trying to use it and if so, how?

1. Why are you not using WEP or WPA to encrypt your Wireless connection? Use it today they you won't have to worry about others using you router.

2. Go and check how many DHCP address have been grabbed. If it is more than the people in you house then some one else is using your router.

Usually you can tell through your wireless router if you have one, but if your computer is set up to receive wireless signals then people won't be able to connect to it directly.

Of course you can see how many people have accessed to your network by their IP address, country profile, program they used, duration they stayed. But I suggest you close your network share with others, because once you opened the share, people within your network can view exactly what you view on your display.

Option 1: Log into your router, depending on your router, look at the DHCP table, it will show you how may computers are connected to your network.

Option 2: Use a free third party software, i recommend look at lan, its free and easy to use, download it at:

http://www.lookatlan.com/download_lal.html

Log into your router and there should be an option to show users within the settings.

If you have some kind of antivirus/spyware software there should be an option which allows you to view other people connected to your network.